Study on the stability of red pigment from polygonum multiflorum thumb

To provide importante raw material for all kinds of new pigment used in food products,cosmetic and leechdom etc.Study on the stability of red pigment from Polygonum multiflorum Thunb?and the condition of extraction.Ethanol was used as the extractant in the extraction,and the pigment stability was investigated by UV.The optimum condition for ethanol extraction is:distilled water was used as the extractant and it was extracted under room temperature for 24h.Theλmax for the pigment was 330nm,which has good solubility in water,bad pH and light resistaance characteritice was observed,however.Some common food additive,such as sodium benzoate,citrate,cane sugar,glucose,acetate,oxidizing agent,reducing agent,metallic ions have no effect on the stability of the pigment.Starch has no effect on its stability